1. Technical Field
This invention pertains to the generation of electromagnetic or other waves of desired frequency bands or the conversion of any such waves to the desired bands. More particularly, it concerns generation of such waves, with desired coherence and modulation and at desired power levels, and conversion to or from radio frequency (RF), terahertz (THz), infrared (IR), visible, ultraviolet (UV), X-rays or even gamma ray bands without the current limitations due to molecular, atomic or subatomic properties of matter.
2. Brief Description of the Prior Art
Hitherto, there has been no general mechanism for generating electromagnetic waves at arbitrarily chosen frequency, coherence, modulation and power level, nor to transform existing waves to achieve such values. Technology becomes increasingly limited at THz and higher frequencies at which the wavelengths become comparable to those of the molecular, atomic and subatomic resonances—although the latter have been used in numerous ways to generate or modify electromagnetic waves, all such ways are limited to what material properties allow for such purposes.
For example, most of the known electromagnetic spectrum is in theory generated by incandescence, but the emitted power at visible or higher frequencies is generally small. Fluorescent lamps are more efficient, but still much too noisy, weak and bulky for high bandwidth communication purposes. Semiconductor light-emitting diodes and lasers cover much of IR and visible spectrum already, and are compact, rugged and efficient, but their spectra are generally confined to specific operating bands defined by the properties of the lasing media. The emerging method of supercontinuum generation promises better coverage, but again depends on nonlinear material properties, and is inefficient and inherently broadband, which may not be suitable for applications requiring specific frequencies. These constraints are generally more severe at THz frequencies, for which there are as yet few mechanisms known for generation in the first place. In addition, signal processing technology well established for audio and RF are difficult to apply at any of these higher frequencies.
As a result, the electromagnetic spectrum has four major divisions today in terms of current technology: RF, where we can manipulate individual waveforms and obtain coherent imaging like synthetic aperture radar (SAR); IR and visible through UV, where we get good focusing, but imaging is generally incoherent, and low noise sources (lasers) exist only for specific frequencies and bands and have low overall efficiencies; X rays and beyond where all sources are generally noisy and there is little in the way of optics; and THz, for which both sources and control of any kind are still largely experimental.
A broad method or mechanism overcoming these constraints of wave generation, or enabling translation of current technological abilities in each of these divisions to the others, is thus desirable. The difficulty, as mentioned, is that these frequencies closely correspond to molecular, atomic and subatomic resonances or bond energies, which have prevented the generation or manipulation of these waves except as permitted by specific molecular, atomic or subatomic structures, their energy levels, permitted photon transitions between these levels, and on related nonlinear properties of the media.